did you know that apparently by common law of farmers, a cat does not belong to anyone, they have no owners, the cat owns the family due to them being roaming animals, unlike to dogs where they belong to a owner, the cats use the house as a sleep/eating spot, thats all.
so my answer is dogs why would you have animal you dont own. no pussy owns me! i own the pussy!
providing exersize for all the DOGS
besides its nice to have at least one person happy to see you after a ****e day at work and teh only reason cats are independent is that the go round scrounging from the neighbours dogs are more than capable of catching food if need be